Patent Application
20180149333
This disclosure relates generally to motor vehicle lighting. More particularly, the disclosure relates to low-profile lighting modules comprising a lens defining a near-zero draft.
Conventional vehicle headlamps such as projector lamps, multi-cavity lamps, and other lighting elements require multiple components such as a light source, light collector, light distributor, etc. Such lighting elements are subject to dimensional constraints associated with the lens shapes required to provide desired collimated lighting patterns, for example low-beams, high-beams, fog lamps patterns, and others. Lens light transmission efficiency is also a design constraint, and conventional vehicle headlamps rarely exceed 50% efficiency, i.e. rarely transmit more than 50% of the light emitted by a light source as a collimated light beam having a desired pattern. Much of the light emitted by the light source is wasted due to poor light collection and destruction of light in the light collector.
Because of this loss of efficiency, headlamps require significant energy usage, equating to higher watt consumption and heat management issues. In turn, smaller profile headlamps meeting regulatory requirements for day/night light intensity, while desirable, cannot be achieved using conventional technology without losing the optical control necessary to control emission of light into desired patterns as described above.
Thus, a need is identified in the art for lighting components allowing such smaller profiles while meeting regulatory requirements for light intensity, and also providing reduced energy usage and light wastage.
In accordance with the purposes and benefits described herein and to solve the above-summarized and other problems, in one aspect a vehicle lighting module is provided, comprising a silicone lens having an input surface and an exit surface, the lens defining a near-zero draft between the input surface and the exit surface. The module further includes a light source. The input surface is configured to shape an incident light emanating from the light source into a collimated light pattern emanating from the exit surface and containing at least 69% of the incident light. The input surface comprises a plurality of multi-faceted near-field lens elements each having a different focal length and each defining a near-zero draft. The exit surface comprises a plurality of micro-optical elements configured to shape the collimated light pattern into a predetermined emitted light pattern.
In embodiments, the predetermined emitted light pattern is one of a low-beam lamp pattern, a high-beam lamp pattern, a fog lamp pattern, a daytime running lamp pattern, and a static bending lamp pattern. In embodiments, one or more of the plurality of micro-optical elements are each 2 mm or less in diameter. In other embodiments, one or more of the plurality of micro-optical elements are each 0.5 mm or less in diameter.
In another aspect, a vehicle headlamp assembly is provided, comprising one or more vehicle lighting modules as described above contained in a housing.
In yet another aspect, a lens for a vehicle lighting module is provided, comprising a silicone lens body defining an input surface and an exit surface, the lens body further defining a near-zero draft between the input surface and the exit surface. As described above, the input surface is configured to shape incident light emanating from the light source into a collimated light pattern emanating from the exit surface containing at least 69% of the incident light. To accomplish this, the input surface comprises a plurality of multi-faceted near-field lens elements each having a different focal length and each defining a near-zero draft. The exit surface comprises a plurality of micro-optical elements configured to shape the collimated light pattern into a predetermined emitted light pattern which can be one of a low-beam lamp pattern, a high-beam lamp pattern, a fog lamp pattern, a daytime running lamp pattern, and a static bending lamp pattern.
In embodiments one or more of the plurality of micro-optical elements are each 2 mm or less in diameter. In other embodiments one or more of the plurality of micro-optical elements are each 0.5 mm or less in diameter. The exit surface may define a quadrilateral shape, a circular shape or other shape.
In the following description, there are shown and described embodiments of the disclosed vehicle lighting modules, lenses therefor, and lighting assemblies comprising the modules. As it should be realized, the modules, lenses, etc. are capable of other, different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the devices and methods as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.
The accompanying drawing figures incorporated herein and forming a part of the specification, illustrate several aspects of the disclosed vehicle lighting modules, and together with the description serve to explain certain principles thereof. In the drawing:
Reference will now be made in detail to embodiments of the disclosed vehicle lighting modules, examples of which are illustrated in the accompanying drawing figures wherein like reference numerals indicate like features.
Use of silicone in fabricating a lens 100 confers other unexpected benefits. In particular, because of silicones' properties of flow and curing, it is possible to provide a lens body 110 having a property of near-zero draft. It will be appreciated that as used herein, “near-zero draft” means no or slightly negative draft. As is known, typically some amount of draft, i.e. a positive angle from a horizontal plane, is required in order to safely extract a molded component from a mold. Absent such draft, the molded component may be difficult to extract and may risk damage during the extraction. Because of the draft in the mold walls, a similar draft is created in the exterior of the molded component.
This is illustrated in
This is further advantageous in the vehicle lighting module arts because significant light (up to 5% of collected incident light) is lost in such draft areas 150. Moreover, such draft areas 150 create glare, further increasing the difficulty of lighting module design. Lacking such draft areas, the lens body 110 of the present disclosure allows improved light transmission and reduced light wastage compared to lenses fabricated of conventional materials.
As is known, light emanating from a light source such as a light-emitting diode (LED) exhibits significant scatter, often in a 180 degree radius from a light emitting portion of the light source. For that reason, the lens body input surface 120 is provided with a plurality of multi-faceted near-field lens elements 160, configured to shape an incident light (see arrows) emanating from a light source (not shown) into a collimated light pattern emanating from the exit surface 130. One or more of the multi-faceted near-field lens elements 160 may define focal lengths that differ from the focal lengths defined by others of the multi-faceted near-field lens elements 160, thus working in conjunction to collimate incident light from one or more light sources (not shown in this view). Exemplary, though non-limiting, designs of multi-faceted near-field lens elements 160 for a lens body input surface 120 as described herein are disclosed in U.S. Pat. No. 9,156,395 to the present assignee, Ford Global Technologies, LLC. The disclosure of U.S. Pat. No. 9,156,395 is incorporated by reference in its entirety herein.
By the multi-faceted near-field lens elements 160 and the superior light transmitting properties of the lens body 110 as described, a collimated light pattern emanating from the exit surface 130 containing 69% or more of the collected incident light is provided, significantly exceeding the capabilities of conventional lenses and lighting modules which struggle to provide 50% efficiency. This allows use of smaller light sources to provide a required amount of light emission, saving energy and reducing generation of heat in a lighting module.
With reference to
Such micro-optical elements 170 allow significantly better light beam control and more precise optics. As a non-limiting example, for an exit surface 130 defining an area of 20×20 mm that directs/spreads/wedges emitted light in one direction, the exit surface including 400 micro-optical elements 170 each defining a 1×1 mm area to individually control emitted light direction/spread/wedge, a 400× increase in control of emitted light is realized.
Still more advantages accrue from use of silicone to fabricate a lens body 110. The lenses 100 depicted in
This can be compared to the dimensions of, for example, a conventional projection beam lighting module wherein the lens has dimensions of 70 mm diameter and 200 mm depth. This allows creation of lighting modules having a significantly smaller size which still provide light emission at the strength, distance, and light spread patterns required by various regulatory agencies, but at a significantly reduced energy cost and heat emission. While newer LED-based projection beam lighting modules may be smaller (for example, 130 mm depth and 50-60 mm aperture), such LED-based modules still require complexity in design (reflectors, shields, and other mechanisms in addition to a lens) compared to crystal designs such as are described herein.
Each lens body 110a, 110b includes an exit surface 130 defining a quadrilateral shape for emitting a collimated light pattern (see arrows). In conventional lighting modules, such quadrilateral exit surface shapes result in significant losses in light transmission efficiency. By the features and benefits described above, such losses in efficiency are avoided and use of more compact quadrilaterally shaped lenses 100 and headlamp assemblies 200 is made possible. However, as will be appreciated use of lens bodies 110 including exit surfaces 130 defining circular shapes is also contemplated.
This is illustrated in
By the above-described features, lenses 100 exhibiting superior light transmission efficiency are provided. In one example, a lens 100 was incorporated into a lighting module 180 including an LED lamp 190 emitting light at 1250 lumens. The lens 100 provided a collimated light pattern output of 860 lumens, which represents 69% light transmission efficiency. In another example, a lens 100 was incorporated into a lighting module 180 including an LED lamp 190 emitting light at 1250 lumens. The lens 100 provided a collimated light pattern output of 900 lumens, which represents 72% light transmission efficiency.
The foregoing has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
